Scores of Travellers removed from the Dale Farm site near Basildon in Essex 12 months ago have suffered mental or physical illness after being forced to live in "squalor" following the controversial eviction, according to a report by MPs.

The report into the living conditions of those forced from the Essex plot during the £7.2m eviction operation found that many have reported health complaints due to unhygienic and unsuitable living conditions. It expressed concern that families who had moved to a nearby plot had no access to toilets. Some even had no electricity and sanitation was judged to be poor.

As a result, the Dale Farm plot is now rat-infested and covered with human excrement, posing a further health hazard. Impetigo, chickenpox and diarrhoea have swept through the encampment, with children affected by vomiting bouts. Residents say many of the women at Dale Farm were prescribed antidepressants before the eviction and, more than a year later, are still on them.

Following a site visit last month by the all-party parliamentary group for Gypsies, Roma and Travellers, MPs say that the health of former Dale Farm residents has deteriorated due to the conditions they have experienced since the eviction. It said: "The delegation found that many of the residents are highly vulnerable and have serious conditions such as Parkinson's disease, dementia, osteoporosis, Crohn's disease, bowel cancer, Down's syndrome etc.

"Members of the Red Cross again stated their continued concerns regarding the physical and mental health of the Travellers, lack of sanitation and the possible health threats posed by the evicted site."

The report said that mothers and young children were particularly vulnerable, with one baby born at the roadside encampment two weeks ago and consternation that midwife visits to women living on the temporary site were suspended for eight months.

Another longer-term health concern follows growing fears that the Environment Agency may have found asbestos on the site. Documents seen by the Observer reveal that soil exhibits taken by Environment Agency officials from Dale Farm plots were recorded as having "suspected asbestos".

The Environment Agency report on whether the eviction uncovered pollutants is expected at the end of the month. Many residents, according to the Gypsy Council, are on repeat courses of antibiotics for chest infections.

Of the 86 families who lived on the Dale Farm site, a largely illegal settlement, around 20 have moved to the temporary camp on a private access road just 100 metres away. A further 20 live nearby on a legal site, while another 20 are travelling in two convoys around the Midlands, where they are frequently moved on by the authorities. The remainder have found accommodation at a caravan site at Fen, Leighton Buzzard, in Bedfordshire, where last year police rescued 24 modern-day slaves from bondage and "filthy and cramped" conditions.

Many of the men have opted to work abroad, leaving women alone to cope with the unsuitable conditions for long periods.

Those who remain at the temporary camp on the roadside near Dale Farm say they have endured psychological anguish since losing their homes. Patrick Egan, who has been unable to work since falling into a ditch on the Dale Farm camp and breaking his ankle, admits he is among those who has sought psychiatric help. He said: "It has got to me."

Despite complaints from nearby villagers that the eviction did little to improve the area, Tony Ball, leader of Basildon council, maintains that the site clearance was not a failure. He said: "The objective of the site clearance was to remedy the illegal development in the area, and this objective was achieved. Clearly, we still have an issue with Travellers living on the Oak Lane roadside who should not be there."

David McPherson-Davis, a parish councillor for the area, is pleased to see at least some of the Travellers go. "Personally I feel the site clearance was good value for money. If it hadn't happened it would have created a precedent for Irish Travellers to occupy land and develop it without any concern for local inhabitants."

Those Travellers living on the roadside have been served with enforcement notices to leave.